Files
30-seconds-of-code/snippets/repeatGenerator.md
Angelos Chalaris c6ed8a48db Add repeatGenerator
2020-10-11 17:05:48 +03:00

28 lines
747 B
Markdown

---
title: repeatGenerator
tags: function,generator,advanced
---
Creates a generator, repeating the given value indefinitely.
- Use a non-terminating `while` loop, that will `yield` a value every time `Generator.prototype.next()` is called.
- Use the return value of the `yield` statement to update the returned value if the passed value is not `undefined`.
```js
const repeatGenerator = function* (val) {
let v = val;
while (true) {
let newV = yield v;
if (newV !== undefined) v = newV;
}
};
```
```js
const repeater = repeatGenerator(5);
repeater.next(); // { value: 5, done: false }
repeater.next(); // { value: 5, done: false }
repeater.next(4); // { value: 4, done: false }
repeater.next(); // { value: 4, done: false }
```